Air compressor systems compress air to pressures above normal atmospheric pressures. Compressor systems generally include several components disposed within a housing. Examples of these components include a motor and drive train assembly, an airend or compressor module, a separator tank, and a fan. The fan creates an air flow through the housing to cool the components of the compressor system and provide air for the airend. The motor may drive the airend through a belt and pulley system that transfers power from the motor to the airend. In some prior art arrangements, the motor is pivotally mounted to the housing and base, and pivots to achieve belt tensioning. In some of those prior art compressor systems, the main motor shaft that drives the airend also drives the fan, but because the motor is pivotally mounted the fan must be a propeller fan due to the tolerances required. Prior art systems which employ a more efficient impeller fan require separate motors to drive the fan and the airend.